Cubic MgH2 stabilized by alloying with transition metals : a density functional theory study
Cubic MgH2 stabilized by alloying with transition metals : a density functional theory study
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DOI：
10.1016/j.actamat.2008.02.028
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发表时间：
2008-08
期刊：
影响因子：
9.4
通讯作者：
B. Pauw;W. P. Kalisvaart;S. Tao;M. Koper;A. Jansen;Phl Peter Notten
中科院分区：
文献类型：
--
作者：
B. Pauw;W. P. Kalisvaart;S. Tao;M. Koper;A. Jansen;Phl Peter Notten
用密度泛函理论研究了mg -过渡金属（Sc, Ti, Zr, Hf）二氢化物两种晶型修饰的稳定性。超过一定的过渡金属含量，纯mgh2的金红石型结构特征不再稳定，氢化物转变为萤石型结构，类似于过渡金属二氢化物。Mg-Sc和Mg-Ti氢化物的转变点估计在20at。% Sc/Ti，这与以前的实验研究非常吻合。对于Mg-Zr和Mg-Hf，没有实验数据可供比较，因此计算对这些体系具有预测价值。对于Zr和Hf，预测其过渡金属含量低于Sc和Ti，为13 at.%。这意味着Mg-Zr氢化物也具有实际意义，因为预测氟石结构氢化物的氢含量超过6wt.%。
The stability of two crystallographic modifications of Mg-transition metal (Sc, Ti, Zr, Hf) dihydrides was studied using density functional theory. Beyond a certain transition metal content, the rutile structure characteristic of pure MgH2is no longer stable, and the hydride transforms into a fluorite-type structure, similar to that of the transition metal dihydride. The transition point for both Mg–Sc and Mg–Ti hydrides is estimated to be at 20at.% Sc/Ti, which is in very good agreement with previous experimental studies. For Mg–Zr and Mg–Hf, no experimental data are available for comparison, so the calculations have a predictive value for these systems. For Zr and Hf, the transition point is predicted to be at lower transition metal content than for Sc and Ti, at 13 at.%. This means that the Mg–Zr hydride is also of practical importance, because a fluorite structured hydride is predicted with a hydrogen content in excess of 6wt.%.